The invention relates to a latch and extractor for use in an electrical socket. In particular, the invention discloses a latch which minimizes the tilt of the circuit board inserted into the slot of the socket.
Electrical sockets having slots for receiving an edge of a circuit card therein are well known in the industry. The sockets generally have latches provided at the ends thereof to maintain a circuit board in the slot of the electrical socket. The sockets are generally of two types, cam-in type sockets in which the circuit board is rotated into position and direct insert sockets in which the circuit board is moved directly into the slot without caming action. Often the latches in the direct insert-type socket also act as extractors.
An example of a direct in socket is shown in U. S. Pat. No. 5,690,499. The patent discloses an electrical socket which has a slot for receiving an edge of a circuit board and a latch/extractor which is movable for dislodging the circuit card from the slot. The socket has a pair of flexible towers, and the extractor has a pair of lateral projections which are received in notches in the towers for locking the extractor in a closed position. The projections have beveled surfaces, and the towers have complementary ramps which are engaged by the beveled surfaces so that the towers are resiliently deflected without damage to the projections. When the extractor is moved to a closed position, edges of a circuit board are maintained between the leg 34 of the extractor. A projection of the extractor also cooperates with a notch in the circuit board to maintain the circuit board in position relative to the socket when the extractor is in the closed position. In so doing, the extractor acts as a latch to maintain the circuit board in position. When the extractor is moved to an open position, the foot cooperates with the bottom of the printed circuit board to help remove the circuit board from the slot of the socket.
While these types of extractors/latches prevent the unwanted removal of the printed circuit board from the socket, these latches do not insure that a positive electrical connection will be maintained between the circuit board and the contacts of the socket. When in use, the sockets and the printed circuit board are exposed to various harmful conditions, such as extreme heat and vibration. As this occurs, the printed circuit board will have a tendency to migrate or rotate from its original position. The prior art latches have been effective to prevent the removal of the circuit board from the socket. However, due to the tolerances required for the manufacture and operation of the latches, the circuit board is able to rotate relative to the contact as the socket and circuit board are exposed to the harsh conditions. If the rotation is not adequately controlled, the electrical connection between the pads of the circuit boards and the contacts of the socket can become intermittent or can fail completely, both of which are unacceptable to the operation of the socket.
It would therefore be beneficial to provide a latch mechanism which minimizes the rotation of the printed circuit board when inserted into the socket. By so doing, the latch would help to insure that a positive electrical connection is effected and maintained over time in various conditions.
The invention is directed to a latch for use in an electrical connector which controls the movement of the circuit board after the circuit board has been inserted into an elongated board receiving slot provided in the housing. The latch cooperates with the circuit board to prevent the inadvertent removal of the circuit board in a direction parallel to the path of insertion of the circuit board. The latch also prevents the inadvertent removal and unwanted movement of the circuit board in a direction perpendicular to the path of insertion, thereby insuring that a positive electrical connection will be effected and maintained between the electrical connector and the circuit board.
The electrical connector has a dielectric housing with a top surface and an elongated slot which is open through the top surface and which is dimensioned to receive an edge of a circuit card therein. At least one latch receiving recess is positioned proximate an end of the elongated slot. In many applications, a latch receiving recess is provided at either end of the elongated slot. The latch receiving recess extends from the top surface of the housing. A first wall of the latch receiving recess is provided adjacent the elongated slot. The first wall has angled surfaces provided thereon. A latch is positioned in the respective latch receiving recess and is pivotally retained therein. Each latch has a pair of legs spaced from each other by a board receiving slot. The legs have a respective tapered surface which extends from a front surface of each leg to a respective side surface. The angle which the tapered surfaces project from the front surface is similar to the angle of the angled surfaces. Whereby when the latch is positioned in locking engagement with the circuit card, the tapered surfaces and angled surfaces cooperate with each other to prevent the movement of the latch and the circuit card in a direction perpendicular to the plane of insertion of the circuit card.
The board receiving slot extends from a front surface of the latch to a back surface. The board receiving slot is dimensioned to receive an end of the circuit card therein, such that the movement of the circuit card in the board receiving slot is controlled.
Locking projections extend laterally from latch side surfaces in directions opposed from each other. The locking projections have lead-in surfaces provided thereon to facilitate movement of the locking projections into and out of locking cavities provided in the latch receiving recesses.
A slot is provided in a back wall of each of the latch receiving recess. The slot is dimensioned to allow the portions of the back wall and side walls to resiliently deform as needed. A back surface of the latch engages the back wall of the latch receiving recess to define a stop position in which the latch is provided in an open position.
The invention is further directed to an electrical connector having a dielectric housing with a top surface and an elongated slot which is open through the top surface and which is dimensioned to receive an edge of a circuit card. At least one latch receiving recess is positioned proximate an end of the elongated slot. The latch receiving recess extends from the top surface. A first wall of the latch receiving recess is adjacent the elongated slot. The first wall has angled surfaces provided thereon. A latch is positioned in the latch receiving recess and is pivotally retained therein. The latch has a pair of legs which are spaced from each other by a board receiving slot. The board receiving slot is dimensioned to receive an end of the circuit board therein and to cooperate with the end of the circuit board to maintain the circuit board in electrical engagement with contacts provided in the dielectric housing. Each leg has a stabilization surface provided thereon. Whereby when the latch is positioned in locking engagement with the circuit card, the stabilization surfaces and angled surfaces cooperate with each other to prevent the movement of the latch and the circuit card in a direction perpendicular to the plane of insertion of the circuit card.
Each stabilization surface extends at an angle from a front surface of each leg to a respective side surface. The angles which the stabilization surfaces project from the front surface is similar to the angle of the angled surfaces.
The invention is further directed to an electrical connector having a dielectric housing with an elongated slot which is dimensioned to receive an edge of a circuit card. At least one latch receiving recess is positioned proximate an end of the elongated slot. A first wall of the latch receiving recess is adjacent the elongated slot. The first wall has angled surfaces provided thereon. A latch is positioned in the latch receiving recess and is movably retained therein. Each latch has a pair of legs spaced from each other by a board receiving slot. The legs have a respective tapered surface which extends from a front surface of each leg to a respective side surface. The angle which the tapered surfaces project from the front surface is similar to the angle of the angled surfaces. Whereby when the latch is positioned in locking engagement with the circuit card, the tapered surfaces and angled surfaces cooperate with each other to prevent the movement of the latch and the circuit card in a direction perpendicular to the plane of insertion of the circuit card.